Running Win 10 Pro 64bit AE and I have had this problem since 4/27 where I attempt to start Firefox but it won't open. I've attached the errors from the MMC. This is what is going on/what I've tried:

Before 4/27 I had no issues opening and closing Firefox.I use Macrim to make full C: drive backups twice a week.Since I was having trouble on 4/27 (backup of C: automatically happened in early AM) I decided to restore the C: drive to the backup of 4/23.Once restore was completed, attempted to open Firefox (success). Closed and tried to reopen - failed. So apparently Firefox would only open once then fail.Restored C: drive to 4/16.(Keep in mind that Firefox was working great up to 4/27).Once restore was complete, attempted to open Firefox (success). Closed and tried to reopen - failed.

So I went back several weeks and what had been working fine is now not working at all. I even installed 64bit Firefox and had the same results, so it's not because of an old installation. Also, one would think that restoring a drive to a prior date that things worked would make things work again but not in this case.

i had messed up my 10pro (for testing purpose) but except edge as an app all browsers working.i would uninstall Norton and MBAM, mbam-cleaner after uninstall -> https://downloads.malwarebytes.org/file/mbam_cleanand look how it would work. or use DISM to repair your windows - i never saw so many times recommended DISM for any windows like 10.